How to extract bitmap out of Direct3D 11 Texture2D object?

Question

I am using the Desktop Duplication API (C++) and have created an output duplication object and further queried the interface for a ID3D11Texture2D object.

I have tried using "D3DX11SaveTextureToFile" and "DirectX::SaveWICTextureToFile" but it gives an error. I need to extract the bitmap or pixel buffer out of this texture so that I can save it as an image. I have tried using a subresource and ID3D11DeviceContext::Map function to extract the pixel buffer but it seems to be empty. But context->Draw() seems to work.

Is there anyway I can extract the pixel buffer/bitmap/image out of the texture2D object?

Thanks!

UPDATE : I solved this using the CaptureTexture function in DirectXTex. You can create a HBITMAP from the resultant ScratchImage

Answer 1

For those who are getting E_NOINTERFACE as their return code from DirectX::SaveWICTextureToFile , you need to initialize COM using one of the following:

HRESULT hr = CoInitialize(nullptr); // Single threaded

HRESULT hr = CoInitializeEx(nullptr, COINITBASE_MULTITHREADED);  // For multithreaded programs

Don't forget to call CoUninialize() after you are done. This is because WIC uses COM and must be initialized before using it.